US2272715A - Means and method of freezing liquids - Google Patents

Description

Feb. 10, 1942. E. E. LINDSEY 2,272,715

MEANS AND METHOD OF FREEZING LIQUIDS Filed July 27, 1940 I 22 F 'Z'Q.G ,24 w XINVENToR H 23 4 ERNEST E. LINDSEY. 4o mill-q}!!! L By 4 ATTORNEYS.

Patented Feb. 1c,- 1942 UNITED STATES, PATEN T OFFICE MEANS AND DIEIHOD OF FREEZING LIQUIDS Ernest E. Lindsey, Los Aiigeles, Calif. Application July 27, 1940, Serial No. 347,982

(Cl. 62-414) J Claims.

My invention relates to a means and method of freezing liquids and more particularly to a means an'd'method of .freezing and chilling confection mixtures at high speed and witha minimum grain size. 2 i

, Among the objects of my invention are: To provide a means and method of freezing liquids such as a confection mixture at high speed; to.

provide a means and method of making frozen confections at high speed and of superior quality;

to provide a means and method of quick freezing a confection in individual units; to provide a quick freezing device operating with a minimum of chatter and vibration; to provide a means and method of scraping frozen material from a refrigerated surface with a minimum of chatter and vibration; to provide a means and methodof producing a fine grained frozen confection.

either continuously or in individual to provide an improved means and method of applying and removing a liquid material such as a confection mixture'to and from a refrigerated surface.

My invention possesses numerous other objects and features of advantage, some of which, to-

gether with the foregoing, will be set forth in the following description of specific apparatus embodying and utilizing my novel method. It is therefore to be understood that my method is applicable to other apparatus, and that I do not volatile liquid may be allowed to expand in space 5, and thus cool the cylinder 4 by abstraction of heat during the expansion of said liquid, as is customary with small refrigeration Cylinder 4 is surrounded by a layerof heat insulating material 9, this insulating material being held in place by cylindrical outer cover In, the latter being attached along the central line to frame I. At the bottom of' cylinder 4 is positioned a con fection receptacle l2 mounted on a swinging arm l3, the latter being pivoted on anupright pin ll so that receptacle l2 may be placed on arm ii to close the bottom of the cylinder], the arm l3 being forced upwardly by spring l5. Frame l is preferably supported in a vertical position by a removable base i6.

Motor shaft 3 is provided with an external cylindrical sleeve ll of substantially shaft length. This sleeve i'l slides over the lower endof the shaft until its upper end abuts shoulder I! on shaft 3. Sleeve H is provided with an upper shoulder 20, and stacked on sl'eeve I! are a plurality of beating and scraping blades 2|, these scraping blades being-preferably made out of strip materialof rectangular section. The blades each comprise a curved portion 22, curved over an arc of slightly more than 180 to externally fit sleeve II, the curved portion then merging into limit myself, in anyway, to the apparatus of the present application, as I may adopt various other apparatus embodiments, utilizing the method,

within the scope of the appended claims. In the drawing:

Fig. 1 is a longitudinal view partly in section and partly in elevation of -a preferred form of my invention.

Fig. 2 is a sectional view taken as indicated by for a more detailed description of my invention,

frame I is provided, carrying at the top a motor 2 having a central shaft 3 extendingdownwardly. Surrounding and concentric with shaft 3 is a hollow cylinder 4, having a space through which a refrigerating fluid may be circulated'by" pipes 6 and I from a refrigeration system 8. Precooled brine may be circulated, or if desired, a 55 lock sleeve II ,to shaft3 by a resilient-portion 23 extending away from sleeve l1 toward the inner surface of the cylinder. Each blade terminated in a planar terminal portion 24', having a scraping edge 25. The scraping edge 25 of this terminal portion is adjacent but not touching the cylinder. wall, preferred spacing be- ,ing from .002 to .0010 inch, and-the terminal portions 24 are twisted with respect'to the remainder of the blade so that the terminal portions are at-an angle to the vertical. Each blade is also provided with a retaining boss 26 on the curved portion 22 thereof. I The plurality of blades are mounted on sleeve ll byprovidin'g sleeve I! with preferably three spiral surface grooves thereon, and stacking blades 2| on the sleeve in staggered relationship;

so that every third blade will have lug 26 in the samegroove. After all of the blades are stacked on slee [1 they are locked in place by applying a pre nut 30 to the bottom of the sleeve.

This pressure nut forces all of the blades upwardly against shoulder 3| of the sleeve and metionally binds them together into a unit. Sleeve I! with the blades thereon may then be held on shaft 2 by bolt 32. To insur that no rotation of the sleeve I] takes place on shaft 3, I prefer to a lock screw 33 having threads partly in sleeve I! and partly in shaft 3.

A convenient way of contouring the blade assemblyis to mount sleeve 11, with the beater bars thereon in a lathe, for example, rotate the sleeve, and then make a light grinding out along the scraping edges 25 thereof, until the scraping edges 25 describe, when rotating, a cylindrical path which is concentric with the inner surface of cylinder 4. 4

The cylinder wall may be refrigerated to any desired temperature depending upon the hard ness of the confection it is desired to deliver to container l2, and with the motor 2 rotating the blade assembly at high speed the confection is poured into funnel 35 running therefrom through delivery pipe 36 into the path of the rotating blades at the top of the cylinder. 'The material is then very finely broken up by the impact of the blades and is thrown against the refrigerated that the non-radial extension of the resilient portion 23 may be curvilinear.

surface whereon it freezes substantially instantaneously. As soon however, as the'layer of frozen material builds up beyond the spacing of the scraping edges from the cylinder wall, the frozen material is immediately scraped off by the scraping edges 25, and is still further finely divided by impact andthrown again onto the cy1 blade be in the opposite direction to the rotation of the driving member. The resilient blade portion 23 may be straight, as shown in Fig. 4 or in the modification shown in Fig. 5, the resilient Consequently, I do not wish to be limited to any particular contour or design of the resilient portions 23, the only requirement being that the scraping edges 25 be resiliently coupled with the driving member.

It will also be noted by reference to Fig, 6 that I have expanded the vertical dimensions of the flat terminal portions 24 carrying the scraping edges 25. This is done for two reasons. I increase the length of the scraping edges so that their paths overlap as shown in Fig. 6, by broken lines and 4|, these lines representing the positions, with respect to a point on the cylindrical surface, taken by three vertically adjacent blades during rotation. Thus all portions of the cylinder wall will surely be scraped, preventing any accumulation of frozen material thereon. The use ofthe expanded portions 24 also provides efl'icient propeller action of the expanded portions 24 to force the material to the lower end of the device without unduly enlarging the section of the resilient portions, which of course, should be kept small so that frozen material will not accumulate thereon.

Thus it will be seen that I have provided a .confection freezer, adapted to.freeze liquids by as a-frozen confection, the consistency of which will depend on freezing temperaturesand speed of motor rotation. Irrespective of consistency however, the frozen-material will be of exceedingly fine grain due to-the intensiv'e beating-action taking place during the progression of the material through the cylinder, and due to the fact that the material, after being deposited on the wall to be frozen, is almost instantaneously removed therefrom, thus preventing a formation of ice crystals of any considerable size. It will be obvious however, that there will be formed on the cylinder wall a skin of hard frozen material between the scraping edges 25 and the refrigerated surface/the thickness of this skin being determined of course by the spacing of the scraping edges from the cylinder walls. Once built up this skin'does not enter into subsequent material during freezing thereof and provides a freezing surface exactly registering with the scraping edges.

I have found that by the use of a resilient coupling between the scraping edges 25 and the motor shaft [that the machine operates exceptionally quietly, and that there is substantially no chatter as is boundto occur when non-re: silient blades are used. With non-resilient blades, scraping resistance tends' to distort .the shaft, and to build up highly undesirable chatter and vibration within the device, possibly due ple the scraping edges 25 to the shaft 3, has entirely eliminated such chatter, and has made a machine in which the shaft runs true, and practically vibration-free within the cylinder during the freezing,-scraping and beating of the gentially from the central driving shaft 3, and

repeated application to a refrigerated surface, and repeated removal therefrom with intermediate beating, which efllciently scrapes frozen material from a refrigerated surface without chatter, and with almost complete elimination of vibration, due to the fact that the scraping edges are resiliently coupled with the driving memrotation of-said rotating means, and terminating adjacent but not touching said surface.

2. Apparatus in accordance with claim 1 .3. Apparatus in accordance with claim 1 wherein saidblades are attached to' said rotating portions enlarged to provide overlapping paths- "to the whip of-the relatively long shaft 3. The

provision of the resilient portions 23, which coumeans in staggered relationship, and wherein said resilient blades are provided with terminal over said surface.

4. Apparatus in accordance with claim 1 wherein said blades are attached to said rotating means in staggered relationship, and wherein said resilient blades are provided with terminal portions enlarged to provide overlapping paths over said ,surfece. said terminal portions being planar and'angularly positioned with respect to th axis of saidcylinder.

5. Apparatus in accordance with claim 1 wherein said rotating means is coaxially positioned in said cylinder, and wherein said resilient blades extend both tangentially and curviadapted to be cooled below the freez-- 7. Apparatus in accordance with claim 1 wherein said rotating means is coaxially positioned in said cylinder and wherein each of said blades has a portion fitting said rotating means over an arc ofgreater than 180 and a free resilient portion 'extending'toward" said surface, said blades being stacked on said rotating means and held thereon by means longitudinally compressing said stack.

' 8. Apparatus in accordance with claim 1 wherein said cylinder and rotating means are coaxial and vertically positioned and wherein said material moves through said cylinder by gravity while being acted upon by said blades,

said blades being resilient only in horizontal planes.

9. Apparatus "in accordance with claim 1 wherein said cylinder and rotating means are coaxial and vertically positioned and wherein said material moves through said cylinder by gravity while being acted upon by said blades, said resilient blades being preformed of strip material.

10. The method of removing frozen material 'from'a refrigerated surface without substantial chatter which comprises moving a scraping edge through said frozen material at high speed without touching said surface and resiliently coupling said edge to the source of power'moving said I edge. I

ERNEST E. LINDSEY.

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